Siemens IMMULITE 2000 AntiCPP IgG Mode D'emploi page 5

Non-reactive: A result less than
4.00 U/mL is considered to be
"nonreactive", and indicates that anti-CCP
IgG antibodies were not detected in the
sample.
The Anti-CCP IgG results determined for a
given specimen with assays from different
manufacturers can vary due to differences
in assay methods and reagent specificity.
Therefore, the results reported by the
laboratory to the physician should include:
"The following results were obtained with
the IMMULITE 2000 Anti-CCP IgG assay.
Results obtained from other
manufacturers' assay methods may not be
used interchangeably."
Expected Values
A total of 197 serum samples from
presumed healthy male (n = 99) and
female (n = 98) donors were analyzed
using the IMMULITE 2000 Anti-CCP IgG
assay. The results from this study suggest
a median of < 1.50 U/mL and a
th
nonparametric 2.5 –97.5
range of < 1.50–1.93 U/mL.
Consider these limits as guidelines only.
Each laboratory should establish its own
reference ranges.
Limitations
Anti-CCP IgG test results alone are not
sufficient to diagnose a patient with
rheumatoid arthritis. Diagnosis should be
made by the physician only after all clinical
and laboratory findings have been
evaluated.
Lipemic, hemolyzed or grossly
contaminated samples may give
erroneous results.
The results in HIV patients, in patients
undergoing immunosuppressive therapy,
or in patients with other disorders leading
to immunosuppression, should be
interpreted with caution.
The performance characteristics of this
assay have not been established for use
with specimens from neonates, cord
blood, or pretransplant patients.
Heterophilic antibodies in human serum
can react with the immunoglobulins
included in the assay components causing
interference with in vitro immunoassays.
[See Boscato LM, Stuart MC. Heterophilic
IMMULITE 2000 Anti-CCP IgG (PIL2KPI-15, 2022-02)
th
percentile
antibodies: a problem for all
immunoassays. Clin Chem 1988:34:27-
33.]. Samples from patients routinely
exposed to animals or animal serum
products can demonstrate this type of
interference potentially causing an
anomalous result. These reagents have
been formulated to minimize the risk of
interference; however, potential
interactions between rare sera and test
components can occur. For diagnostic
purposes, the results obtained from this
assay should always be used in
combination with the clinical examination,
patient medical history, and other findings.
Performance Data
See Tables and Graphs for data
representative of the assay's performance.
Results are expressed in U/mL. (Unless
otherwise noted, all were generated on
serum samples collected in tubes without
gel barriers or clot-promoting additives.)
Reportable Range: 1.50–200 U/mL
The assay is traceable to an internal
standard manufactured using qualified
materials and measurement procedures.
Analytical Sensitivity: Limit of Blank
(highest value expected for a sample with
no analyte; determined in accordance with
10
CLSI EP17-A ): 0.26 U/mL
Limit of Detection (lowest detectable
concentration; determined in accordance
10
with CLSI EP17-A ): 1.50 U/mL
Functional Sensitivity: (concentration
with 20% coefficient of variation (CV)
10
determined): 2.34 U/mL
Precision: Precision was evaluated
according to CLSI guideline EP5-A2.
Serum samples were assayed in duplicate
over the course of 20 days, two runs per
day, using 3 lots for a total of 40 runs and
80 replicates. (See Precision table.)
Specificity: The specificity assessment of
the IMMULITE 2000 Anti-CCP IgG assay
was conducted on 8 subgroups of patients
(n = 40) with potentially cross-reacting
conditions and disease states where other
autoantibodies may be present in the
patient samples. The following disease
states were evaluated: Systemic Lupus
Erythematosus (SLE), Sjogren's
Syndrome, Lyme Disease, Osteoarthritis,
Scleroderma, Polymyositis, Thyroiditis and
Mononucleosis.
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